Needle Roller and Cage Assemblies for Crank Pins and Piston Pins

Needle roller and cage assemblies for crank pins and piston pins

Page Product overview Needle roller and cage assemblies for crank pins and piston pins...... 2

Features Needle roller and cage assemblies for crank pins ...... 3 Needle roller and cage assemblies for piston pins ...... 3 Special designs ...... 3

Design and safety guidelines Guidance of the connecting rod...... 4 Design of adjacent parts ...... 5 Preferred enveloping circle diameter of needle roller and cage assemblies ...... 5 Calculation of rolling bearings in crank mechanisms...... 6 Design brief for crank mechanism bearing arrangements ...... 7

Accuracy Geometrical tolerances ...... 8 Radial internal clearance...... 10 Sort plan for crank pin bearing arrangements ...... 10 Sort plan for piston pin bearing arrangements ...... 11

Ordering example, ...... 11 ordering designation

Dimension tables Needle roller and cage assemblies for crank pins ...... 12 Needle roller and cage assemblies for piston pins ...... 13

Schaeffler Technologies TPI 94 1 Product overview Needle roller and cage assemblies for crank pins and piston pins

For crank pins KZK 000B6D9C

For piston pins KBK 000B6FE7

2 TPI 94 Schaeffler Technologies Needle roller and cage assemblies for crank pins and piston pins

Features Needle roller and cage assemblies for connecting rod bearing arrangements are used in the crank mechanisms of 2 and 4 stroke engines as well as in compressors for supporting crank pins and piston pins. They consist of cages equipped with needle rollers, support high centrifugal and acceleration forces and are suitable for high speeds. They require very little radial space since the radial section height only corresponds to the diameter of the needle rollers. They give bearing arrangements with high runout accuracy which is, however, influenced by the geometrical accuracy of the raceways. The radial internal clearance is dependent on the needle sort as well as the shaft and housing tolerances and can be adjusted by means of the needle roller sort.

Needle roller and Needle roller and cage assemblies for crank pins are externally cage assemblies for guided, which means that the connecting rod bore guides the cage crank pins radially with defined clearance. The radial movement of the cage in relation to the connecting rod bore and the rolling elements is as small as possible. The cages are made from quenched and tempered steel, have good wear resistance, exhibit high strength and their large guidance surfaces are designed for optimum lubrication.

Needle roller and Needle roller and cage assemblies for piston pins are internally cage assemblies for guided, which means that the piston pin guides the cage radially piston pins with defined clearance. Due to their small radial internal clearance, tilting of the connecting rod is reduced to a minimum. The needle roller and cage assemblies support high frequency oscillating loads and are available for the majority of piston pin diameters in various widths, in accordance with the piston boss spacing. The steel cages are case hardened or quenched and tempered, exhibit good wear resistance and have high strength.

Further information For further information on needle roller and cage assemblies: ■ Catalogue HR 1, Rolling Bearings.

Special designs Depending on the performance requirements, variants are possible in relation to: ■ material ■ heat treatment ■ coating ■ cage profile ■ needle roller profile.

Further information For further information on coatings: ■ TPI 186, Higher Performance Capacity Through the Use of Coatings.

Schaeffler Technologies TPI 94 3 Needle roller and cage assemblies for crank pins and piston pins

Design and safety guidelines Guidance of Depending on which parts of the crank mechanism are guided the connecting rod laterally by the connecting rod, a distinction is drawn between crank end guidance and piston end guidance.

Crank end guidance The connecting rod and needle roller and cage assembly KZK are guided axially between the crank webs, Figure 1. The connecting rod eye at the crank end must have lubrication pockets and slots to allow the supply of lubricant. Free lateral movement of the connecting rod and needle roller and cage assembly KBK between the piston bosses must be ensured taking account of all tolerances.

Figure 1 Crank end guidance: Lateral guidance of the connecting rod

between the crank webs 000B6DAE Piston end guidance The connecting rod and needle roller and cage assembly KBK are guided axially between the piston bosses, Figure 2. Free lateral movement of the piston rod and needle roller and cage assembly KZK between the crank webs must be ensured taking account of all tolerances. In order to ensure good radial guidance of the needle roller and cage assembly KZK, the large connecting rod eye must be matched to the width of the needle roller and cage assembly KZK.

Figure 2 Piston end guidance: Lateral guidance of

the connecting rod 000B6DB9

4 TPI 94 Schaeffler Technologies Design of adjacent parts The bores and pins for the needle roller and cage assemblies must be produced as rolling bearing raceways. A roughness Rz 1 (Ra 0,2) must be ensured. The raceways must be hardened, ground and, depending on the application, honed. The rolling elements and guidance surfaces of the cage must also be supported over their entire length by the raceways. A minimum case hardening depth of 0,5 mm and a minimum surface hardness of 700 HV must be observed for all raceways and thrust surfaces. In addition, the lateral thrust surfaces should be precision machined (maximum Ra 0,2 recommended) and wear resistant (thrust washers should be fitted if necessary). For lubrication of the needle roller and cage assemblies, holes or lubrication pockets should be provided, with additional lubrication slots for the crank end guidance.

Proven materials for adjacent parts Adjacent part Material Connecting rod 16MnCr5, 15CrNi6 Crank pin 15Cr3, 17Cr3, 15CrNi6 Piston pin Ck15, 15Cr3, 17Cr3

Preferred enveloping circle The dimensions of the needle roller and cage assemblies KZK and diameter of needle roller and KBK are determined by factors including the capacity of the cylinder. cage assemblies The preferred enveloping circle diameters Fw of needle roller and cage assemblies for proven diameters of crank pins and piston pins are given for 2 stroke engines, see table. Other enveloping circle diameters may be available if sufficient quantities are required.

Proven enveloping circle Capacity per cylinder Enveloping circle diameter Fw for diameters for 2 stroke engines KZK KBK cm3 mm mm over incl. from to from to – 35 8 14 8 12 35 50 12 16 10 12 50 100 16 20 12 14 100 150 18 22 14 16 150 200 22 24 16 18 200 300 24 28 18 22 300 – 28 – 20 – In order to design needle roller and cage assemblies for a specific engine, the technical data of the engine must be taken into consideration. The design brief for crank mechanism bearing arrangements must therefore be completed. The design brief is available online, see link, page 7.

Schaeffler Technologies TPI 94 5 Needle roller and cage assemblies for crank pins and piston pins

Calculation of rolling bearings The basic rating life and adjusted reference rating life are available in crank mechanisms for the calculation of rolling bearings in crank mechanisms. We recommend calculating the adjusted reference rating life in preference.

Fatigue theory as a principle The rating life calculation standardised in ISO 281 is based on Lundberg and Palmgren’s fatigue theory, which always gives a final rating life. However, modern, high-quality bearings can exceed by a consider- able margin the values calculated in accordance with standard ISO 281 under favourable operating conditions. Ioannides and Harris have developed a further model of fatigue in rolling contact that expands on the Lundberg and Palmgren theory and gives a better description of the performance capability of modern bearings.

Basic rating life Our calculation method can be used to calculate the basic rating life L10 of the bearings (needle roller and cage assemblies for crank pins and piston pins, main bearings) in the crank mechanism of internal combustion engines on the basis of DIN ISO 281. In comparison with the standardised calculation to DIN ISO 281, it additionally takes into consideration the influence of internal load distribution in the bearing on the rating life. The calculation method takes account of dynamic loading (gas forces and inertia, external forces acting on the crankshaft) and the movement functions in crank mechanisms. Simplifications underlying the calculation model are as follows: ■ the crankshaft is only subjected to propulsion units of identical load and geometry, articulated connecting rods are not taken into consideration ■ statically determinate crankshaft bearing arrangement with two bearings ■ no account taken of lubrication influences ■ no account taken of geometrical imperfections and deformations of the surrounding parts.

Adjusted reference rating life It is also possible to calculate the adjusted reference rating life Lnmr in accordance with DIN ISO 281, Appendix 4. This calculation method additionally incorporates the fatigue limit load of the material, the lubrication conditions and the type and size of contamination. Further data is required in this case. Please contact Schaeffler.

Further information For detailed information on the calculation methods: ■ Catalogue HR 1, Rolling Bearings.

6 TPI 94 Schaeffler Technologies Design brief for In order to be able to support you in designing needle roller and crank mechanism bearing cage assemblies for a specific engine, the relevant technical data of arrangements the engine is required. The design brief used to record this data is available online via the following link.

000B6E72 http://bit.ly/2qSVKWx

Schaeffler Technologies TPI 94 7 Needle roller and cage assemblies for crank pins and piston pins

Accuracy Geometrical tolerances The geometrical tolerances of the raceways must be observed, see tables, Figure 3 and Figure 4, page 9.

Permissible geometrical Nominal diameter of Tolerance t of cylindricity for tolerance values for the crank pin crank pin bearing arrangements dB dB DB (crank pin) (connecting rod bore) mm ␮m ␮m over incl. 8 14 2 3 14 18 2 3 18 22 3 5 22 25 4 5 25 30 4 7 30 – 4 7

0,04/100 C

t t 1 C

DB H6(G6) E dB ᕃ Crank end guidance 0,04/100 A–B Figure 3 Geometrical tolerances for A B crank pin bearing arrangements 000B6DC2

8 TPI 94 Schaeffler Technologies Permissible geometrical Nominal diameter of Tolerance t of cylindricity for tolerance values for the piston pin piston pin bearing arrangements dA dA DA (piston pin) (connecting rod bore) mm ␮m ␮m over incl. 8 14 2 3 14 18 2 3 18 22 4 5

t t

DA K6 E dA

0,04/100 C 2

dB ᕄ Piston end guidance 0,04/100 A–B Figure 4 Geometrical tolerances for A B piston pin bearing arrangements 000B6DCB

Schaeffler Technologies TPI 94 9 Needle roller and cage assemblies for crank pins and piston pins

Radial internal clearance The radial internal clearance can be set using the appropriate needle roller sort; sort plans can be used for this purpose, see tables. Example of determination of the radial internal clearance using the mean value of the needle roller sort: ■ needle roller sort 0 –2, mean value –1.

Crank pin bearing arrangements The radial internal clearance is dependent on the speed, rigidity and accuracy of the crankshaft parts. Minimum values for radial internal clearance must be achieved, see table, page 11. Do not exceed the tolerance range of 0,015 mm. For very high speeds (for example in racing engines), please contact Schaeffler.

Piston pin bearing arrangements The radial internal clearance must be at least 0,002 mm and must not exceed 0,012 mm.

Sort plan for crank pin bearing Conditions: arrangements ■ bore tolerance G6 for 18 mm to 30 mm in three groups ■ pin tolerance h5 for 14 mm to 18 mm in three groups ■ needle roller sort 0 –2 to –5 –7 ■ radial internal clearance 17 ␮m to 30 ␮m.

Sort plan for crank pin bearing Characteristics Bore deviations arrangements +7 +11 +11 +15 +15 +20 ␮m ␮m ␮m 0 0 0 Crank pin deviation –3 –3 –3 Needle roller sort –4 –6; –5 –7 –2 –4; –3 –5 0–2; –1–3 Radial internal clearance 17 to 26 17 to 26 17 to 27 –3 –3 –3 Crank pin deviation –6 –6 –6 Needle roller sort –4 –6; –5 –7 –1 –3; –2 –4 0–2; –1–3 Radial internal clearance 20 to 27 18 to 27 20 to 30 –6 –6 –6 Crank pin deviation –8 –8 –8 Needle roller sort –1 –3; –2 –4 0–2; –1–3 0–2 Radial internal clearance 17 to 25 19 to 27 23 to 30

10 TPI 94 Schaeffler Technologies Sort plan for piston pin bearing Conditions: arrangements ■ bore tolerance K6 for 10 mm to 18 mm in three groups ■ pin tolerance 0 –6 in three groups ■ needle roller sort 0 –2 to –5 –7 ■ radial internal clearance 3 ␮m to 12 ␮m.

Sort plan for piston pin bearing Characteristics Bore deviations arrangements –9 –5 –5 –1 –1 +2 ␮m ␮m ␮m 0 0 0 Piston pin deviation –2 –2 –2 Needle roller sort –5 –7 –3 –5; –4 –6 –1 –3; –2 –4 Radial internal clearance 3 to 9 3 to 11 3 to 10 –2 –2 –2 Piston pin deviation –4 –4 –4 Needle roller sort –4 –6; –5 –7 –2 –4; –3 –5 0 –2; –1 –3 Radial internal clearance 3 to 11 3 to 11 3 to 10 –4 –4 –4 Piston pin deviation –6 –6 –6 Needle roller sort –3 –5; –4 –6 –1 –3; –2 –4 0 –2; –1 –3 Radial internal clearance 3 to 11 3 to 11 5 to 12

Radial internal clearance, Nominal dimension Crank pin bearing Piston pin bearing minimum values arrangement arrangement

dB 2 stroke 4 stroke mm ␮m ␮m ␮m over incl. 8 14 14 10 2 14 18 17 12 2 18 22 20 14 2 22 25 24 18 2 25 30 28 20 – 30 – 30 25 –

Ordering example, Needle roller and cage assembly KZK for: ordering designation ■ crank pin 16 mm ■ connecting rod bore 22 mm ■ width 12 mm ■ needle roller sorts (sort pair coded blue) –2 –4 and –3 –5 ■ copper plated cage. Ordering designation KZK16ϫ22ϫ12 SORT–2–4/–3–5–CU

Schaeffler Technologies TPI 94 11 Needle roller and cage assemblies for Bc crank pins

Ew Fw 000B6DD4 KZK

Dimension table · Dimensions in mm Dimensions Basic load ratings Fatigue Mass Designation1)2) limit load

FW EW BC dyn. stat. Cur m Cr C0r N N N Ϸ g 8 12 8 3900 3 400 415 0,0022 KZK8ϫ12ϫ8 10 14 10 4150 3 900 485 0,0046 KZK10ϫ14ϫ10 12 16 10 6400 7 200 880 0,0035 KZK12ϫ16ϫ10 12 17 10 7400 7 400 980 0,005 KZK12ϫ17ϫ10 13 17 10 7400 7 400 890 0,004 KZK13ϫ17ϫ10 14 18 10 7100 8 500 1 060 0,004 KZK14ϫ18ϫ10 14,4 20,4 10 8100 7 800 930 0,0065 KZK14,4ϫ20,4ϫ10 15 21 11,15 10 100 10 600 1 290 0,009 KZK15ϫ21ϫ11,15 16 21 10 8200 9 200 1 210 0,006 KZK16ϫ21ϫ10 16 22 10 9200 9 500 1 140 0,0077 KZK16ϫ22ϫ10 16 22 12 11 000 11 900 1 670 0,0098 KZK16ϫ22ϫ12 18 24 12 11 600 13 100 1 840 0,01 KZK18ϫ24ϫ12 18 24 13 12 100 13 800 1 740 0,0125 KZK18ϫ24ϫ13 19 25 15 13 000 15 400 1 870 0,015 KZK19ϫ25ϫ15 20 28 16 17 900 19 700 2 350 0,026 KZK20ϫ28ϫ16 22 28 13 13 900 17 500 2 490 0,015 KZK22ϫ28ϫ13 22 28 16 15 600 20 200 2 500 0,018 KZK22ϫ28ϫ16 22 29 16 17 800 21 800 2 850 0,02 KZK22ϫ29ϫ16 23,1 28,1 14 13 100 18 600 2 250 0,011 KZK23,1ϫ28,1ϫ14 25 32 16 18 200 23 100 3 050 0,0244 KZK25ϫ32ϫ16 25,1 30,1 14 14 000 20 800 2 500 0,013 KZK25,1ϫ30,1ϫ14 26 31 16 17 200 27 500 3 400 0,016 KZK26ϫ31ϫ16 26 33 14 19 100 24 900 3 200 0,023 KZK26ϫ33ϫ14 28 33 14 14 800 23 100 2 800 0,014 KZK28ϫ33ϫ14 28 35 17 21 700 30 000 3 700 0,033 KZK28ϫ35ϫ17 28 35 18 23 400 33 000 4 200 0,027 KZK28ϫ35ϫ18 28 36 14 20 300 25 000 3 950 0,028 KZK28ϫ36ϫ14 28 36 16 23 300 30 000 3 650 0,03 KZK28ϫ36ϫ16 30 38 16 22 800 30 000 3 500 0,032 KZK30ϫ38ϫ16 30 38 18 25 500 35 000 4 250 0,035 KZK30ϫ38ϫ18 Other dimensions available by agreement.

1) The needle roller and cage assemblies are available by agreement only (subject to availability). Production is dependent on economically viable quantities. 2) The designation describes the dimensions only. For a precise ordering designation, please contact Schaeffler.

12 TPI 94 Schaeffler Technologies Needle roller and cage assemblies for Bc piston pins

Ew Fw 000B6DDD KBK

Dimension table · Dimensions in mm Dimensions Basic load ratings Fatigue Mass Designation1)2) limit load

FW EW BC dyn. stat. Cur m Cr C0r N N N Ϸ g 8 11 10 3450 3 450 435 3 KBK8ϫ11ϫ10 9 12 10 3700 3 900 495 4 KBK9ϫ12ϫ10 9 12 11,7 4200 4 600 620 4 KBK9ϫ12ϫ11,7 9 13 12,5 6000 6 100 780 4,3 KBK9ϫ13ϫ12,5 10 13 12,5 5000 5 900 700 4 KBK10ϫ13ϫ12,5 10 13 14,5 5400 6 600 900 4 KBK10ϫ13ϫ14,5 10 14 10 4800 4 700 590 4,6 KBK10ϫ14ϫ10 10 14 12,7 6500 6 900 850 5 KBK10ϫ14ϫ12,7 10 14 13 6000 6 200 760 5,8 KBK10ϫ14ϫ13 11 14 15 6600 8 600 1798 3 KBK11ϫ14ϫ15 12 15 15 6000 7 900 1090 5 KBK12ϫ15ϫ15 12 15 17,5 7800 11 000 1580 6 KBK12ϫ15ϫ17,5 12 16 13 6900 7 800 1010 7 KBK12ϫ16ϫ13 12 16 16 8000 9 500 1180 8 KBK12ϫ16ϫ16 12 17 13 7600 7 700 950 8 KBK12ϫ17ϫ13 12 17 14,4 9600 10 400 1280 8,5 KBK12ϫ17ϫ14,4 13 16 14 6200 8 300 990 5,5 KBK13ϫ16ϫ14 13 17 14,5 8500 10 400 1280 8 KBK13ϫ17ϫ14,5 13 17 17,5 9100 11 300 1430 10 KBK13ϫ17ϫ17,5 14 17 20 9400 14 700 1910 8 KBK14ϫ17ϫ20 14 18 17 9100 11 600 1400 9 KBK14ϫ18ϫ17 15 19 17 8900 11 500 1440 9 KBK15ϫ19ϫ17 15 19 19,5 10 600 14 600 1860 12,6 KBK15ϫ19ϫ19,5 15 19 20 11 300 15 500 2100 12,8 KBK15ϫ19ϫ20 15 19 24 12 400 17 600 2300 11 KBK15ϫ19ϫ24 16 20 20 11 800 16 900 2280 13 KBK16ϫ20ϫ20 18 22 22 13 500 20 700 2800 16,9 KBK18ϫ22ϫ22 18 22 24 14 100 22 000 3050 18 KBK18ϫ22ϫ24 18 23 23,15 16 700 23 500 2900 22 KBK18ϫ23ϫ23,15 20 25 22 16 200 23 300 3050 20 KBK20ϫ25ϫ22 20 25 23,15 17 400 25 500 3150 28 KBK20ϫ25ϫ23,15 22 27 25 20 500 32 500 4100 30 KBK22ϫ27ϫ25 Other dimensions available by agreement.

Schaeffler Technologies TPI 94 13 Schaeffler Technologies AG & Co. KG Industriestraße 1–3 91074 Herzogenaurach Germany All information has been carefully compiled and www.schaeffler.de/en checked by us, but we cannot guarantee complete [email protected] accuracy. We reserve the right to make corrections. Therefore, please always check whether more up-to-date or amended information is available. In Germany: This publication supersedes all deviating infor- Phone 0180 5003872 mation from older publications. Printing, including excerpts, is only permitted with our permission. From other countries: © Schaeffler Technologies AG & Co. KG Phone +49 9132 82-0 TPI 94 / 01 / en-GB / DE / 2021-03